An electric and thermal energy network that exploits both electric and thermal energy for desirable overall performance connects, for example, a combined heat and power system (CHP) (e.g., a gas-powered electric generator), a renewable energy source (RES) (e.g., a photovoltaic device and a wind-powered electric generator), an electric storage unit (e.g., one that includes a rechargeable battery), a thermal accumulation unit (e.g., one that includes a heating storage device or a cooling storage device), an electric power grid (electric power supply network) (e.g., a commercial electric power system), a thermal energy supply system (e.g., a gas boiler, an electric cooling device, an absorption cooling device), an electric load (e.g., a server device), and a thermal load (e.g., a room heating device).
Such an electric and thermal energy network exhibits low energy supply efficiency, hence high energy supply cost unless, for example, CHPs are managed in accordance with various conditions either in thermal power-led operation, in which the CHP follows thermal power demand, or in electric power-led operation, in which the CHP follows electric power demand, so as to achieve an effective combination of energy supply efficiency and energy supply cost. Unless the CHPs are thus managed, optimally efficient management and optimal energy management would be impossible.
In relation to this inconvenience, Patent Document 1 discloses an energy management system that minimizes energy cost by fuzzy logic when both electric and thermal energy are exploited for desirable overall performance by balancing energy supplies from an electric power grid, CHPs, and RES's and energy demands by electric and thermal loads.
On the same note, Patent Document 2 discloses an energy control system that uses fuzzy logic to determine, among other factors, at what power level to operate each distributed generator and when to store energy.